We investigated the effect of deviant stimulus probability on the somatosensory magnetic mismatch negativity (MMNm) using an electrical two-point stimulation. First, we determined the discrimination threshold (DT) of the two-point distance. We applied standard stimuli at a distance that subjects felt as one point and deviant stimuli at a distance that subjects definitely felt as two points. We used three deviant stimulus probabilities, 10, 30, and 50%. The components peaking around 30-70 ms (first component) and 150-250 ms (fourth component) following deviant stimuli were significantly larger than those following standard stimuli in 10% condition, but not in 30 or 50% condition. The equivalent current dipole (ECD) was located in the contralateral primary somatosensory cortex (cSI) for the first component, and in the cSI and in the contralateral secondary somatosensory cortex (cSII) for the fourth component. The peak amplitude of the MMNm decreased as the probability of the deviant stimulus increased. The Somatosensory MMNm was affected by deviant stimulus probability similar to an auditory mismatch negativity (MMN).
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Front Hum Neurosci
November 2024
Graduate School of Engineering and Science, Shibaura Institute of Technology, Tokyo, Japan.
Introduction: The ASME (stands for Auditory Stream segregation Multiclass ERP) paradigm is proposed and used for an auditory brain-computer interface (BCI). In this paradigm, a sequence of sounds that are perceived as multiple auditory streams are presented simultaneously, and each stream is an oddball sequence. The users are requested to focus selectively on deviant stimuli in one of the streams, and the target of the user attention is detected by decoding event-related potentials (ERPs).
View Article and Find Full Text PDFBiol Psychol
November 2024
Institute of Cognitive Neuroscience and Psychology, HUN-REN Research Centre for Natural Sciences, Magyar tudósok körútja 2, Budapest H-1117, Hungary. Electronic address:
Visual mismatch negativity (vMMN), the difference between the event-related potentials (ERPs) to repeated (standard) events and changing (deviant) events, can be caused either by diminished activity to the repeated ones (stimulus-specific adaptation, SSA), increased activity to the new ones, or both effects. To determine which of these effects contribute to the emergence of vMMN, we investigated the effect of repetition on visual ERPs. To this end, we measured electrical brain activity to task-irrelevant stimuli both in case of stimulus onset (continuously present objects, ON-events) and stimulus offset (frequently or infrequently disappearing parts of the objects, OFF-events).
View Article and Find Full Text PDFCogn Neurodyn
October 2024
Department of Biomedical Engineering, NIT Raipur, Raipur, India.
Unlabelled: Attentional paradigm can have a significant influence on the processing and experience of positive and negative emotions. Attentional mechanism refers to the tendency to selectively attend to a particular stimulus while ignoring others. In the context of emotions, individuals may exhibit attentional biases towards either positive or negative emotional stimuli.
View Article and Find Full Text PDFBrain Sci
September 2024
NeuroHeuristic Research Group, University of Lausanne, Quartier UNIL-Chamberonne, 1015 Lausanne, Switzerland.
Brain Sci
September 2024
Department of Neuroscience, Faculty of Advanced Technologies in Medicine, Iran University of Medical Sciences, Tehran 1449614535, Iran.
Altered sensory processing especially in the auditory system is considered a typical observation in children with autism spectrum disorder (ASD). Auditory temporal processing is known to be impaired in ASD children. Although research suggests that auditory temporal processing abnormalities could be responsible for the core aspects of ASD, few studies have examined early time processing and their results have been conflicting.
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